1. Field
Example embodiments relate to semiconductor devices, and more particularly, to semiconductor devices using a 2-dimensional electron gas (2DEG) and a 2-dimensional hole gas (2DHG), and methods of manufacturing the semiconductor devices.
2. Description of the Related Art
A gallium nitride (GaN)-based power device is one of the prime candidates for replacing a general silicon radio frequency (RF) and power device. The GaN-based power device may be used as an RF power amplifier or a switching device. When used as a switching device, the GaN-based power device may be used to drive various motors, and may be used to control a current flow in a power conversion system that converts an alternating current (AC) to a direct current (DC), DC to AC, or DC to DC. Accordingly, efficiencies of RF and power conversion systems may be dependent upon efficiencies of amplifying and switching devices.
A switching device that is currently used is a power metal oxide semiconductor field effect transistor (MOSFET) or an insulated gate bipolar transistor (IGBT) using silicon. Thus, an increase in the efficiency of the switching device may be limited due to the limitation of silicon as a material.
Accordingly, there have been attempts to increase a conversion efficiency by manufacturing a transistor using a GaN semiconductor. However, it is not only difficult to manufacture a bulk GaN wafer but there is also a limit to a size of a substrate. Thus, a method of growing a GaN layer on a silicon substrate is currently used.
A GaN switch that is mostly used is an n-type device that is manufactured via n-type device epitaxial growth. Accordingly, it is difficult to form an n-type GaN switch and a p-type GaN switch on the same substrate, and thus, it is difficult to highly integrate a semiconductor device and an application range of the semiconductor device may be limited.